Collar stay



FIG. 1 is an isometric view of a COLLAR STAY showing my new design;

FIG. 2 is a front elevation view thereof;

FIG. 3 is a rear elevation view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is top view thereof; and

FIG. 7 is a bottom view thereof.

CLAIM The ornamental design for a COLLAR STAY as shown and described.